646238449 has 2 divisors, whose sum is σ = 646238450. Its totient is φ = 646238448.

The previous prime is 646238423. The next prime is 646238473. The reversal of 646238449 is 944832646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 578883600 + 67354849 = 24060^2 + 8207^2 .

It is a cyclic number.

It is not a de Polignac number, because 646238449 - 2⁷ = 646238321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 646238399 and 646238408.

It is not a weakly prime, because it can be changed into another prime (646236449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323119224 + 323119225.

It is an arithmetic number, because the mean of its divisors is an integer number (323119225).

Almost surely, 2^646238449 is an apocalyptic number.

It is an amenable number.

646238449 is a deficient number, since it is larger than the sum of its proper divisors (1).

646238449 is an equidigital number, since it uses as much as digits as its factorization.

646238449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 46.

The square root of 646238449 is about 25421.2204467055. The cubic root of 646238449 is about 864.5648959464.

The spelling of 646238449 in words is "six hundred forty-six million, two hundred thirty-eight thousand, four hundred forty-nine".